Viral infection and interferons can induce the expression of 2′, 5′-oligoadenylate synthetases (OAS) (Rebouillat et al., 1999). These OAS proteins are expressed “ubiquitously” in humans and mice. In humans, there are three reported OAS genes (small, OAS1; medium, OAS2; and large, OAS3) and one OAS-like gene (OASL) which are linked on human chromosome 12. There are two mouse OAS genes (Oas1A and Oas1B) that arose from a gene duplication and encode “small” OAS proteins, as well as an OAS-like gene (Oasl5). OASL5 protein is 60% identical to mouse OAS1A and 1B (Shibata et al., 2001) but distinct from human OASL. The three human OAS proteins and the mouse OAS proteins, except OASL or OASL5, share the ability to convert ATP into 2′, 5′-linked oligomers of adenosine (2–5A) in the presence of double stranded (ds) RNA. GTP can also act as a substrate for OAS, though the in vivo significance of this is not understood. 2–5A oligomers bind and activate RNAse L leading to degradation of viral and cellular RNA and thereby downregulating protein production. However, it is not known if OAS or OAS-like proteins have RNAse L-independent antiviral activities or function in cellular processes unrelated to viral infection (i.e., degradation of oocyte mRNA species after fertilization).
Thus, the inventors of the present invention have identified an OAS related family member and provide the first indication that oligoadenylate synthetase-like proteins function in gametogenesis and early embryonic development. It is envisioned that modulation of this protein play a role in contraception, fertility, cell proliferative disease, i.e., cancer, or other reproductive diseases.